Vertical shaft impact crushers (VSI-crushers) are used in many applications for crushing hard material like rocks, ore, etc. WO 2004/020103 describes a VSI-crusher comprising a housing and a horizontal rotor located inside the housing. Material that is to be crushed is fed vertically into the rotor via a hopper, a feeding chamber and a feed tube. With the aid of centrifugal force the rotating rotor ejects the material against the wall of the housing, and on impact with the wall the material is crushed to a desired size.
Replacement of the feed tube, which is a wear part, is an expensive, complicated, and time consuming operation, typically involving lifting an upper portion of the crusher, including the hopper, with a crane.